The present invention generally relates to a method for identifying a certain state or condition of an engine soak timer and more particularly, to a method which identifies a xe2x80x9cshort timexe2x80x9d type state or condition of an engine soak timer by the use of an engine coolant temperature signature.
A soak timer is used within a vehicular control assembly to determine the amount of time that an engine, such as an internal combustion engine, has been deactivated. Particularly, the information which is provided by the timer is used to determine whether the engine has remained inoperative for a sufficient period of time in order to allow several diagnostic tests, such as a fuel vapor emission test which requires the engine and associated components and constituent materials to be relatively cool, to be conducted.
A xe2x80x9cshort timexe2x80x9d state, within the soak timer, causes the soak timer to erroneously determine that the engine has ceased operation for a period less than the period necessary to allow these tests to be properly conducted, thereby substantially always preventing these tests from being accomplished. The term xe2x80x9cstatexe2x80x9d as used in this application means a certain condition of the soak timer.
While some attempts have been made to detect the occurrence of a xe2x80x9cshort timexe2x80x9d state within a soak timer, these attempts are relatively complicated, are relatively costly, and are not reliable.
It is a first non-limiting advantage of the present invention to provide a method for identifying a xe2x80x9cshort timexe2x80x9d state within a vehicle control assembly in a manner which overcomes some or all of the previously delineated disadvantages of prior methods.
It is a second non-limiting advantage of the present invention to provide a method for identifying a xe2x80x9cshort timexe2x80x9d state within a vehicle control assembly in a manner which overcomes some or all of the previously delineated disadvantages of prior methods and which, by way of example and without limitation, utilizes an engine coolant temperature signature.
It is a third non-limiting advantage of the present invention to provide a method for identifying a xe2x80x9cshort timexe2x80x9d state within a vehicle control assembly in a manner which overcomes some or all of the previously delineated disadvantages of prior methods and which, by way of example and without limitation, inferentially creates a temperature value and uses the inferentially created temperature value along with a previously measured and/or created temperature value to identify the existence of a xe2x80x9cshort timexe2x80x9d state.
According to a first non-limiting aspect of the present invention, a method for identifying the existence of a short time state within a controller assembly is provided. The method includes the steps of determining a first temperature at a first time; determining a second temperature at a second time; comparing the first and the second temperatures; and ascertaining the existence of the short time state by use of the comparison.
According to a second non-limiting aspect of the present invention, a method for identifying the existence of a certain state within a vehicle control assembly is provided. The method includes the steps of creating a signature; determining the temperature of material resident within a vehicle; using the signature to create a value; comparing the created value with the previously determined temperature; and identifying the existence of the state based upon the comparison.
These and other aspects, features, and advantages of the present invention will become apparent from a reading of the following detailed description of the preferred embodiment of the invention and by reference to the following drawings.